Abstract

An abnormal structure of the ZnSe nanowheels composed of teethlike extended patterns on nanoring bases has been successfully synthesized by thermal evaporation method. It is interesting to note that the as-synthesized ZnSe nanowheels are metastable wurtzite phase with the dominant exposed surfaces of while the stable ZnSe is typically zinc blende phase. A full picture of the growth mechanism of the metastable wurtzite phase ZnSenanostructures will be proposed from the thermodynamic point of view. Meanwhile, the formation of the nanowheels is also explained by a two-stage mechanism. In the first stage, the base of the nanowheel begins to form by vapor-solid mechanism, while in the second stage, the teethlike extended structures grow through the self-catalyzed growth process. The cathodoluminescence spectrum of ZnSe nanowheel exhibited a band edge transition at about and a strong self-activated luminescence at . It is important to note that the discussions of the nanostructure thermodynamics and stability can be applied to understand the growth mechanism of other nanostructures which are critical for optimization of the nanostructures.

Received 05 March 2007Accepted 30 June 2007Published online 17 August 2007

Acknowledgments:

This work was supported by the University Development Fund (UDF) and the seed funding of the University of Hong Kong. One of the authors (T.I.Y.) thanks the support of seed funding from the University of Hong Kong. The authors thank the discussion with I. Markov supported by William Mong Visiting Fellowship of the University of Hong Kong.